Hyponatremia is a prognostic marker for specific pathologies. However, the association between contrast-induced nephropathy (CIN) and post-procedural hyponatremia has not been explored. Our study aims to evaluate the association between hyponatremia developing after contrast media administration and CIN.

A total number of 236 patients who required nephrology consultation before coronary angiography (CAG) or percutaneous coronary intervention (PCI) because of the high risk for contrast nephropathy, were included. Serum sodium levels were measured at admission and within three consecutive days after contrast media administration.

Hyponatremia was observed in 141patients (59.7%) following angiography. CIN was developed in 149 (63.4%) patients. Among the patients who developed hyponatremia, ejection fraction, serum haemoglobin level and serum albumin level were low whereas, contrast media volume and percentage of the diabetes mellitus were higher. Also, length of hospital stay, percentage of CIN, renal replacement requirement and mortality rate were higher in patients with hyponatremia. In univariable analysis to evaluate the risk factors for CIN, being female gender, age, diabetes mellitus, serum albumin concentration, haemoglobin level, contrast media volume and hyponatremia were associated with development of CIN. Multivariable logistic regression analysis revealed that advanced age, serum albumin concentration and hyponatremia were independent predictors of CIN.

Post-procedural hyponatremia was an independent risk factor for CIN in CAG or PCI patients.